/* $Id$ */
/*
   +----------------------------------------------------------------------+
   | PHP Version 7                                                        |
   +----------------------------------------------------------------------+
   | Copyright (c) 1997-2015 The PHP Group                                |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 of the PHP license,      |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | http://www.php.net/license/3_01.txt                                  |
   | If you did not receive a copy of the PHP license and are unable to   |
   | obtain it through the world-wide-web, please send a note to          |
   | license@php.net so we can mail you a copy immediately.               |
   +----------------------------------------------------------------------+
   | Authors: Pierre Alain Joye  <pajoye@php.net                          |
   +----------------------------------------------------------------------+
 */

/*
 * License for the Unix md5crypt implementation (md5_crypt):
 *
 * ----------------------------------------------------------------------------
 * "THE BEER-WARE LICENSE" (Revision 42):
 * <phk@login.dknet.dk> wrote this file.  As long as you retain this notice you
 * can do whatever you want with this stuff. If we meet some day, and you think
 * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
 * ----------------------------------------------------------------------------
 *
 * from FreeBSD: crypt.c,v 1.5 1996/10/14 08:34:02 phk Exp
 * via OpenBSD: md5crypt.c,v 1.9 1997/07/23 20:58:27 kstailey Exp
 * via NetBSD: md5crypt.c,v 1.4.2.1 2002/01/22 19:31:59 he Exp
 *
 */

/*
 * This has been modified to be used exclusively by MSVC
 * for HHVM. It has also been reformatted for HHVM's coding
 * standards.
 */

#include <string.h>
#include <Windows.h>
#include <wincrypt.h>

#include <signal.h>
#include "php-crypt_r.h"
#include "crypt-freesec.h"

void _crypt_extended_init_r() {
  LONG volatile initialized = 0;

  if (!initialized) {
    InterlockedIncrement(&initialized);
    _crypt_extended_init();
  }
}

/* MD% crypt implementation using the windows CryptoApi */
#define MD5_MAGIC "$1$"
#define MD5_MAGIC_LEN 3

static unsigned char itoa64[] =    /* 0 ... 63 => ascii - 64 */
  "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

static void
to64(char *s, int v, int n) {
  while (--n >= 0) {
    *s++ = itoa64[v & 0x3f];
    v >>= 6;
  }
}

char* php_md5_crypt_r(const char *pw, const char *salt, char *out) {
  HCRYPTPROV hCryptProv;
  HCRYPTHASH ctx, ctx1;
  unsigned int i, pwl, sl;
  const BYTE magic_md5[4] = "$1$";
  const DWORD magic_md5_len = 3;
  DWORD        dwHashLen;
  int pl;
  __int32 l;
  const char *sp = salt;
  const char *ep = salt;
  char *p = NULL;
  char *passwd = out;
  unsigned char final[16];

  /* Acquire a cryptographic provider context handle. */
  if(!CryptAcquireContext(&hCryptProv, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT)) {
    return NULL;
  }

  pwl = (unsigned int) strlen(pw);

  /* Refine the salt first */
  sp = salt;

  /* If it starts with the magic string, then skip that */
  if (strncmp(sp, MD5_MAGIC, MD5_MAGIC_LEN) == 0) {
    sp += MD5_MAGIC_LEN;
  }

  /* It stops at the first '$', max 8 chars */
  for (ep = sp; *ep != '\0' && *ep != '$' && ep < (sp + 8); ep++) {
    continue;
  }

  /* get the length of the true salt */
  sl = (unsigned int)(ep - sp);

  /* Create an empty hash object. */
  if(!CryptCreateHash(hCryptProv, CALG_MD5, 0, 0, &ctx)) {
    goto _destroyProv;
  }

  /* The password first, since that is what is most unknown */
  if(!CryptHashData(ctx, (BYTE *)pw, pwl, 0)) {
    goto _destroyCtx0;
  }

  /* Then our magic string */
  if(!CryptHashData(ctx, magic_md5, magic_md5_len, 0)) {
    goto _destroyCtx0;
  }

  /* Then the raw salt */
  if(!CryptHashData( ctx, (BYTE *)sp, sl, 0)) {
    goto _destroyCtx0;
  }

  /* MD5(pw,salt,pw), valid. */
  /* Then just as many characters of the MD5(pw,salt,pw) */
  if(!CryptCreateHash(hCryptProv, CALG_MD5, 0, 0, &ctx1)) {
    goto _destroyCtx0;
  }
  if(!CryptHashData(ctx1, (BYTE *)pw, pwl, 0)) {
    goto _destroyCtx1;
  }
  if(!CryptHashData(ctx1, (BYTE *)sp, sl, 0)) {
    goto _destroyCtx1;
  }
  if(!CryptHashData(ctx1, (BYTE *)pw, pwl, 0)) {
    goto _destroyCtx1;
  }

  dwHashLen = 16;
  CryptGetHashParam(ctx1, HP_HASHVAL, final, &dwHashLen, 0);
  /*  MD5(pw,salt,pw). Valid. */

  for (pl = pwl; pl > 0; pl -= 16) {
    CryptHashData(ctx, final, (DWORD)(pl > 16 ? 16 : pl), 0);
  }

  /* Don't leave anything around in vm they could use. */
  RtlSecureZeroMemory(final, sizeof(final));

  /* Then something really weird... */
  for (i = pwl; i != 0; i >>= 1) {
    if ((i & 1) != 0) {
      CryptHashData(ctx, (const BYTE *)final, 1, 0);
    } else {
      CryptHashData(ctx, (const BYTE *)pw, 1, 0);
    }
  }

  memcpy(passwd, MD5_MAGIC, MD5_MAGIC_LEN);

  if (strncpy_s(passwd + MD5_MAGIC_LEN, MD5_HASH_MAX_LEN - MD5_MAGIC_LEN, sp, sl + 1) != 0) {
    goto _destroyCtx1;
  }
  passwd[MD5_MAGIC_LEN + sl] = '\0';
  strcat_s(passwd, MD5_HASH_MAX_LEN, "$");

  dwHashLen = 16;

  /* Fetch the ctx hash value */
  CryptGetHashParam(ctx, HP_HASHVAL, final, &dwHashLen, 0);

  for (i = 0; i < 1000; i++) {
    if(!CryptCreateHash(hCryptProv, CALG_MD5, 0, 0, &ctx1)) {
      goto _destroyCtx1;
    }

    if ((i & 1) != 0) {
      if(!CryptHashData(ctx1, (BYTE *)pw, pwl, 0)) {
        goto _destroyCtx1;
      }
    } else {
      if(!CryptHashData(ctx1, (BYTE *)final, 16, 0)) {
        goto _destroyCtx1;
      }
    }

    if ((i % 3) != 0) {
      if(!CryptHashData(ctx1, (BYTE *)sp, sl, 0)) {
        goto _destroyCtx1;
      }
    }

    if ((i % 7) != 0) {
      if(!CryptHashData(ctx1, (BYTE *)pw, pwl, 0)) {
        goto _destroyCtx1;
      }
    }

    if ((i & 1) != 0) {
      if(!CryptHashData(ctx1, (BYTE *)final, 16, 0)) {
        goto _destroyCtx1;
      }
    } else {
      if(!CryptHashData(ctx1, (BYTE *)pw, pwl, 0)) {
        goto _destroyCtx1;
      }
    }

    /* Fetch the ctx hash value */
    dwHashLen = 16;
    CryptGetHashParam(ctx1, HP_HASHVAL, final, &dwHashLen, 0);
    if(!(CryptDestroyHash(ctx1))) {
      goto _destroyCtx0;
    }
  }

  ctx1 = (HCRYPTHASH) NULL;

  p = passwd + sl + MD5_MAGIC_LEN + 1;

  l = (final[ 0]<<16) | (final[ 6]<<8) | final[12]; to64(p,l,4); p += 4;
  l = (final[ 1]<<16) | (final[ 7]<<8) | final[13]; to64(p,l,4); p += 4;
  l = (final[ 2]<<16) | (final[ 8]<<8) | final[14]; to64(p,l,4); p += 4;
  l = (final[ 3]<<16) | (final[ 9]<<8) | final[15]; to64(p,l,4); p += 4;
  l = (final[ 4]<<16) | (final[10]<<8) | final[ 5]; to64(p,l,4); p += 4;
  l = final[11]; to64(p,l,2); p += 2;

  *p = '\0';

  RtlSecureZeroMemory(final, sizeof(final));


_destroyCtx1:
  if (ctx1) {
    if (!CryptDestroyHash(ctx1)) {

    }
  }

_destroyCtx0:
  CryptDestroyHash(ctx);

_destroyProv:
  /* Release the provider handle.*/
  if(hCryptProv) {
    if(!(CryptReleaseContext(hCryptProv, 0))) {
      return NULL;
    }
  }

  return out;
}
